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Subject: search.filters.subject.Tawharanui Regional Park

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    The impact of Paradise shelducks (Tadorna variegata) on pastoral communities and their role as reservoirs af agricultural diseases : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Conservation Ecology, Massey University, Auckland
    (Massey University, 2007) Delaney, Mark Pierre
    Since its habitat expansion, due to human land clearance for farmland, paradise shelducks (Tadorna variegata) have established a firm foothold in the New Zealand agricultural environment. Paradise shelducks feed primarily on agricultural pasture and consequently compete directly with livestock for resources. As a result many farmers consider paradise shelducks to be a pest. In addition, it is a common perception that paradise shelducks contaminate agricultural land with their faeces. Although there is a wealth of information on the impacts of waterfowl on agricultural industries and diseases associated with waterfowl, no studies have specifically looked at the potential impact paradise shelducks pose on New Zealand's agricultural practices. The aims of this study were to 1) determine the presence and prevalence of pathogenic micro-organisms in paradise shelduck faeces and their associated environment, 2) evaluate the findings in terms of transmission routes and the relative risk to livestock and humans, 3) determine whether paradise shelducks have an affect on primary pasture production and composition, and 4) estimate the daily food intake rates of paradise shelducks. This study was based on a population of paradise shelducks in Tawharanui Regional Park over each of four seasons from 2006-2007. The prevalence of pathogenic micro-organisms was determined by paradise shelduck faecal surveys for selected bacteria and parasites. Surveys were conducted for flock birds and breeding pairs Additionally, faecal samples of sympatric species and water troughs were analysed. The impacts of paradise shelducks on pastoral communities was assessed by means of an exclusion experiment, consisting of two types of exclosure; a 'closed' exclosure to exclude all animals including paradise shelducks, and an 'open' exclosure to exclude livestock, but to allow access for paradise shelducks. Daily food intake rates for paradise shelducks were estimated from observational foraging data and necropsies ot paradise shelducks. Results show that no isolates of Salmonella. Campylobacter Yersinia. Cyrptospordium or Giardia were found. Relatively low prevalences of non haemolytic and alpha haemolytic Streptococci. Enterococcus, Bacillus, Clostridium perfringens, Proteus mirablis, strongyle eggs and Coccidia eggs were found. Additionally. E. coli was consistently isolated from the faecal samples throughout the sampling period. However, the serotypes of the micro-organisms isolated were not determined, so no conclusions could be drawn in relation to their pathogenicity. Furthermore, no significant correlations were found between the number of accumulated faeces sampled and the presence or prevalences of the micro-organisms isolated. It also appears that sampling during the driest times of the year will yield the highest presence of micro-organisms in paradise shelduck faeces. An array of micro-organisms, similar to those found in paradise shelduck faeces, were found in pukekos and house sparrow faeces as well as high contamination levels of faecal indicators in troughs. No conclusive transmission routes for the micro-organisms were found. Paradise shelducks were found to have a significant impact on pasture production and to selectively graze white clover (Trifolium repens). Furthermore, it was estimated that the paradise shelducks had a foraging intake rate of 104±15g/day of pasture dry matter. The results confirmed that paradise shelducks can have an affect on agricultural land. A more long term study in different regions is required to evaluate the full extent to which paradise shelducks affect agricultural production in New Zealand.
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    An integrated approach for predicting the fate of reintroduced populations : a thesis presented in partial fulfilment of the requirements for the degree of Masters of Science in Conservation Biology at Massey University, Palmerston North, New Zealand
    (Massey University, 2017) Drummond, Faline
    I provide a comprehensive account of the fate of a reintroduced population of North Island robins (Petroica longipes) at Tawharanui Regional Park, a predator-free peninsular site in the Auckland Region. All factors affecting the success of reintroductions do so through survival, reproduction, or dispersal. I use an integrated Bayesian approach to assess the impact these factors have on population persistence. I estimated population growth by combining vital rates (survival and reproduction) using 9 years of post-release monitoring data. There was no change to estimates when informative priors that accounted for site-to-site variation were included. I determined that despite low recruitment, the population will persist under current circumstances. I then focused on what was causing low recruitment by distinguishing juvenile survival from permanent natal dispersal. Habitat fragmentation prevented juvenile dispersal out of the park, and juvenile survival was low with most mortality occurring within four months of fledging. It is low juvenile survival that is causing low recruitment, indicating the habitat quality is marginal. Despite this, current habitat quality and connectivity is sufficient to maintain a population, but there may be implications for management if connectivity is increased in the future. Finally, I assessed whether it would be sensible to harvest this population as their location makes them a convenient source for future reintroductions. I projected population dynamics 10 years into the future and examined the implications of a one-off harvest on population persistence. Whilst there was negligible chance that the population would go extinct, a harvest at any level reduced the number of females in the population throughout the 10 years, with larger harvests causing a greater reduction. My results can be used within a decision analysis framework to facilitate the decision of whether Tawharanui would be a suitable source population for future reintroductions.
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    Analysing gecko monitoring data and standardising monitoring procedures at Shakespear, Tawharanui and Whakanewha Regional Parks : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Environmental Management, Massey University, Auckland, New Zealand
    (Massey University, 2015) Chamberlain, Elizabeth
    Constant inventories of New Zealand gecko populations are important to monitor the status of the populations over time and allow diagnosis of declines in abundance. Long-term monitoring can also provide information on how effective different management schemes are for conserving a species. Populations of Pacific geckos (Dactylocnemis pacificus) are monitored at Shakespear and Whakanewha, and populations of forest (Mokopirirakau granulatus) and green geckos (Naultinus elegans) are monitored at Tawharanui and Whakanewha on a yearly basis. Whakanewha has a poison based regime for controlling predators, and Tawharanui and Shakespear are largely reliant on predator-proof fences. Visual encounter surveys (VESs) provide a relative abundance estimate of the gecko populations in terms of catch per unit effort (CPUE). There was no significant change in CPUE over the three years of monitoring (2012-2014) for any of the gecko populations. It is a possibility this could be a result of small statistical power tests. Comparisons of abundance indices could not be made between parks due to the likely difference of detectability in different vegetation types. Despite the change in activity levels of some animal species during different phases of the moon, this study found that the same phenomenon does not occur for green and forest geckos. There was no significant difference in the CPUE of the gecko species from VESs conducted during the new and full moon. Therefore, there is no need to stratify VESs based on the moon phases in order to account for changes in the activity levels of the geckos when obtaining abundance indices. Tracking tunnels have proven an effective monitoring device for estimating the distribution and relative abundance of animal species and have increasingly been used to monitor lizard species. Its use for detecting arboreal geckos has not been completed with any great success. One Pacific gecko was detected in this study using tracking tunnels designed for arboreal geckos, a very low tracking rate. Cell foam retreats (CFRs) were also used for detecting geckos. They were able to detect the presence of all gecko species at the three parks that were detected by VESs except for one instance: CFRs failed to detect the presence of green geckos at Whakanewha. Therefore, it is advisable that they are not used exclusively for monitoring the gecko populations.